Option to skip external css export to Anki to save space

[Gilfaro]

(Describe the feature or change)
When exporting dictionaries a lot of duplicated external css is exported for each card which adds a lot of space (10-50kB per card per dictionary with external css). If the user moves the css to the Anki template they can save a lot of space with bigger decks.
Add an option to export the dictionary as is with styling information but without external css like glossary-plain (for all dictionaries) or glossary-XXX-plain (for single dictionary, maybe nocss suffix?